Advances in treating adolescent problem behaviors have resulted in an increased emphasis on redirecting resources to transport evidence-based treatments (EBTs) into clinical practice settings. Efforts to transport efficacious interventions and evaluate the effectiveness of EBTs in global regions where adolescent drug abuse and delinquency represent challenges have been rare. Additionally, training of scientists in developing countries to strengthen the research infrastructure can provide the framework for introducing and maintaining EBTs in these countries. Studies have revealed that adolescent drug use is growing exponentially in many countries in South America, including Chile. However, no EBTs for drug abuse have yet been transported to or developed there. There is consensus, however, among Chilean researchers, mental health leaders, and governmental agencies that adopting EBTs for drug abuse and related problems is a critical next step to improving treatment outcomes nation-wide. The confluence of a ready clinical infrastructure, laws favoring drug treatment availability, and scientists poised and motivated to develop a research expertise to implement and evaluate treatments places Chile in a unique position to pursue research evaluating EBTs for drug abusing youth. One intervention approach that holds great promise for dissemination and evaluation in Chile is Functional Family Therapy (FFT), a widely-disseminated intervention program for youth with behavior problems that is supported by more than three decades of research. The effectiveness of FFT for adolescents with conduct/delinquent behaviors has been replicated across sites, settings, and service providers with diverse backgrounds and training. Further, FFT is a well established treatment for adolescent substance abuse and has been shown to be particularly efficacious for Hispanic American families in the United States. Thus, the overarching goals of the proposed research are to: 1) evaluate the feasibility and promise of FFT, as implemented by community-based practitioners in Santiago, Chile, on adolescent drug use and conduct/delinquent behaviors, and 2) to mentor Chilean scientists within a collaborative effort to extend their expertise to clinical areas with the long term goal of conducting randomized clinical trials (RCTs) in the treatment of adolescent substance abuse themselves. Families (n=32) of drug abusing adolescents referred to outpatient treatment facilities in Santiago, will receive SAU (services as usual) or FFT+SAU (FFT in the context of usual services). The three specific clinical aims of this project are: 1) To examine differences between FFT+SAU vs SAU in improving treatment outcomes for both delinquency and drug abuse. 2) To examine differences between FFT+SAU and SAU in improving families' engagement and retention in treatment. 3) To examine differences between FFT+SAU and SAU in improving family functioning. The successful completion of this project will provide a foundation for future RCT research led by Chilean scientists. PUBLIC HEALTH RELEVANCE: Adolescent drug use in Chile has grown dramatically in recent years and effective treatments are urgently needed. The proposed study is designed to evaluate the implementation of an evidence-based family treatment adapted to Chilean cultural customs and practices. The collaborative aspects of this study will foster the development of research capacity in a developing country.